Comparison of theTONOVETPlus®, TonoVet®, and Tono‐Pen Vet™ tonometers in normal cats and cats with glaucoma

Abstract

ObjectivesTo determine the accuracy, precision, and clinical applicability of the ICare® TONOVET Plus (TVP) in cats.Animals and ProceduresIOP readings obtained with the TVP were compared to values obtained concurrently with the original TONOVET (TV01) and Tono‐Pen Vet™ (TP) in 12 normal cats (24 eyes) and 8 glaucomatous LTBP2‐mutant cats (13 eyes) in vivo. Reproducibility of TVP readings was also assessed for three observers in the above cats. The anterior chambers of five different normal cat eyes were cannulated ex vivo. IOP was measured with the TVP, TV01, and TP at manometric IOPs ranging from 5 to 70 mmHg. Data were analyzed by linear regression, ANOVA and Bland–Altman plots. ANOVA was used to assess reproducibility of TVP readings obtained by different observers and an ANCOVA model controlled for variation of individual cats. p < .05 was considered significant.ResultsTVP values strongly correlated with TV01 values (y = 1.045x + 1.443, R2 = .9667). The TP significantly underestimated IOP relative to the TVP and TV01, particularly at high IOP. IOP values obtained by 1 observer were significantly higher (~1 mmHg average) compared to the other 2 observers via ANCOVA analysis (p = .0006479 and p = .0203). Relative to manometry, the TVP and TV01 were significantly more accurate (p < .0001) and precise (p < .0070) than the TP in ex vivo eyes.ConclusionsIOP readings obtained with the TVP and TV01 are broadly interchangeable between models and between observers, but subtle differences may be important in a research context. TP readings vastly underestimate high IOP in feline glaucoma.

Comparison of Tonovet® and Tonovet plus® tonometers for measuring intraocular pressure in dogs, cats, horses, cattle, and sheep

“…Kiland et al . [ 5 ] compared IOP values in normal and glaucomatous cats, showing a strong correlation between TonoVet® and TonoVet Plus®. TonoVet® showed slightly higher IOP values than TonoVet Plus® [ 5 ].…”

“…[ 5 ] compared IOP values in normal and glaucomatous cats, showing a strong correlation between TonoVet® and TonoVet Plus®. TonoVet® showed slightly higher IOP values than TonoVet Plus® [ 5 ]. Our results showed no significant differences between IOP values measured using TonoVet® and TonoVet Plus®.…”

“…IOP ranges can be found in literature for TonoPet® (New York, USA), TonoVet®, and recently some reports for TonoVet Plus®, mainly in dogs and cats [ 4 , 5 ]. Because previously published reference ranges for IOP in healthy animals are device-specific, using any of the devices, it is strongly recommended to use appropriate reference values according to the device.…”